I never really understood the following of Plasma TV's until I finally saw someone with one calibrated properly. Yes, the picture was very impressive. Sadly there were many uncalibrated low quality plasma TV's sold and the market was killed for them.
So what do you have to choose from now.
Well, the LCD answer to Plasma is FLAD. The problem with LCD is that as the pixels themselves do not glow, you need to have a back light to shine through the screen with the LCD blocking the light to give the colour picture on the screen. All is good but black can only be as black as the amount of light that can be blocked and white can only be as white as the total brightness of the back light. A compromise at best. FLAD moves the back lighting from being around the sides to being an array of smaller LED blubs covering the whole back panel of the TV that can be turned on and off in grid arrays. This means that when displaying darker parts on a screen, the blacks can be blacker as the back lighting for that particular section can be turned off so less background light is there to illuminate the LCD filter.
So, if you are looking at LCD for your next TV and want better dynamic range, then FLAD is the way to go.
But then you get into the HD vs UHD. Is getting 4K going to give you a better picture. Well, this is where some things get fun. 4K does give more detail and though some disagree, there are those of us that can tell the difference between 1080p and 2160p. The other thing that is coming into play is the possibility of the expanded colour space taking the picture from 8bit/channel to 10bit/channel and upping from NTSC/709 colour space to a better DCS/REC2020 that allows the TV to display colours that simply were not possible to produce before. To get that added colour you must move to the newer 4K TV set.
The down side to the move up however is historic video footage. I have current 1080p HTPC media center that stores a copy of all my old movies and TV shows. The 4K tv however needs to upscale the video from all my lower res sources to display. Up-ressing from a 1080p or 720p material is very good, Going from a 480p is pretty good but pushing the limits. So a DVD does look watchable but you can tell that it is not nearly as sharp as it should be. Your TV enhances the loss or resolution in 4K far more than an older HD 1080 tv ever did.
Where the real problem comes in is bad quality DVD's or any item that you ripped and compressed as that process reduced and eliminated much of the detail that was close but would not have been seen at a lower resolution, but when you try and upscale it to 4K ends up looking awful.
Any the problem gets worse. If you try and play this media on a device that itself upscaled to 1080p (that many media players do) on your 4K TV your picture will be so fuzzy it will be almost unwatchable. This is because the TV then tried to upscale an already upscaled picture and hell breaks loose.
If I play a re-compressed DVD on my Kodi media player with the screen res set to 1080p, I get a far worse picture than if I re-set the media player to output at the native 480p res for the media player and let the TV do a single upress to the 4K.
Just figured I would put some experience out there and see if anyone else had had the same results.
